Right in Earth’s neighborhood, space is positively bubbling with
high-energy antimatter particles--a lot more than can be explained.
These excess positrons--mirror opposites of negatively charged
electrons--just might be signals of dark matter.

They might not be, though, and right now scientists are not sure. But the news of excess positrons is still good news from the Alpha Magnetic Spectrometer,
one of the largest and most expensive physics experiments in history.
From its post on the International Space Station, flying some 220 miles
above Earth, the AMS could be on the verge of helping cosmologists
explain what dark matter is made of.

Right now, the best news that the $2(ish) billion AMS works, and that
it’s settled the question of whether there really is an excess of these
positrons. Its first results were announced in a seminar at CERN, near
Geneva. Samuel Ting, its 77-year-old investigator and the main reason
AMS exists, is publishing the data explaining these “new physical
phenomena” in Physical Review Letters.